Search results for "Dehydrohalogenation"
showing 4 items of 4 documents
Regioselective Synthesis of Mono- and Dispiropyrazoline Derivatives via 1,3-dipolar Cycloaddition with Nitrilimines
2016
The 1,3-dipolar cycloaddition reaction of (E,E)-1,3-bis(arylidene)indan-2-one with diarylnitrilimines, generated in situ via dehydrohalogenation of the corresponding hydrazonoyl chlorides , affords predominantly monospiropyrazolines and as a mixture of diastereoisomers. Also dispiropyrazolines are formed in moderate yields. The structure and stereochemistry of cycloadducts were confirmed by 1H and 13C-NMR spectroscopy, elemental analyses data, and single-crystal X-ray diffraction studies of and .
Herstellung von 1,5‐Cyclooctadiin und 1,3,5,7‐Cyclooctatetraen aus 1,5‐Cyclooctadien
1994
Preparation of 1,5-Cyclooctadiyne and 1,3,5,7-Cyclooctatetraene from 1,5-Cyclooctadiene Bromination of 1,5-cyclooctadiene (1) and stepwise dehydro-bromination first with KOtBu and then with KOtBu/18-crown-6 yields 1,5-cyclooctadiyne (5). A prolonged interaction of the base causes a complete transformation to cyclooc-tatetraene (6). Diyne 5 and even more the intermediate enyne 4 are highly reactive dienophiles. The cycloadducts 10–14 formed with 1,3-cyclohexadiene, carbon disulfide, and tetraphenylcyclopentadienone were isolated and characterized. Treatment of 5 with titanium tetrachloride induces a vigorous polymerization.
Lactones. Part 15: Synthesis of chiral spirolactones with a carane system—insect feeding deterrents
2002
Abstract Starting from (+)-3-carene 1 several spirolactones with carane backbone were synthesized. δ-Hydroxy-γ-lactone 5 was obtained by acidic lactonization of a γ,δ-epoxy ester. Iodolactone 8 and bromolactone 9 were products of iodolactonization of γ,δ-unsaturated acid 7 and bromolactonization of γ,δ-unsaturated ester 3 respectively. The halo lactones were subjected to reductive dehalogenation with tributyltin hydride and dehydrohalogenation with DBU. The structures of the lactones obtained were confirmed by X-ray analysis and spectral data.
Synthesis, Crystal Structure, Thermal Analysis and Magnetic Behavior of a Novel One‐Dimensional Polymeric Pyridinium Chlorocuprate( II ): (Hpy) 2 [Cu…
2003
A one-dimensional polymeric pyridinium chlorocuprate (HPy)2[Cu3Cl8(H2O)2], an intermediate between (HPy)CuCl3 and CuCl2·2H2O, has been synthesized and characterized by X-ray analysis [monoclinic, P21/c, a = 7.8950(10), b = 14.144(2), c = 9.921(10) A, β = 99.20(2)°]. The structure contains [Cu3Cl8(H2O)2]n2n− chains in which both square-pyramidal and octahedral CuII exist. The chains are composed of linked [Cu2Cl6]2− dimers and CuCl2(H2O)2 monomeric units. On being heated in the solid state the compound undergoes dehydration followed by dehydrohalogenation to produce a pyridine complex of CuII: [Cu3Py2Cl6]. Other compounds, (HPy)2[CuCl4], CuPyCl2 and CuPy2Cl2, also produce [Cu3Py2Cl6] as an i…